Packaged photocurable composition

ABSTRACT

A photocurable composition is provided which includes al having bottom and side walls which define a chamber a photocurable material disposed in-the chamber. The wall circulmacribe the bottom wall and includes a rant so that the side wall will substantially attenuate nic radiation while minimally attenuating visible light ng an approximating spectral wavelength greater than nanometers. By that arrangement, the level of the ocurable material may be visualized through the side while still providing sufficient attenuation of nic radiation to provide for long term storage of the ocurable material without substantial curing thereof.

CROSS-REFERENCED TO RELATED APPLICATIONS

This Patent Application is a continuation of application Ser. No.09/122,677 filed Jul. 27, 1998, now U.S. Pat. No. 5,996,796 which is acontinuation-in-part Application of an application entitled PACKAGEDPHOTOCURABLE COMPOSITION, Ser. No. 08/743,646, filed Nov. 4, 1996, nowU.S. Pat. No. 5,785,178.

BACKGROUND OF THE INVENTION

1. Field Of The Invention

This invention relates to a packaged photocurable composition thatincludes a squeezable vial having a chamber that receives a quantity ofphotocurable material.

2. Description of the Related Art

Many liquid and semi-liquid compositions used in small quantities in thehousehold, commercial or industrial applications are sold in smallvials, such as dropper bottles, squeezable applicators and the like.Typically, such vials are relatively inexpensive and are disposed ofonce their contents have been exhausted or have not been used by aspecified expiration date.

Many small vials used for containing and dispensing liquid andsemi-liquid compositions are made of a flexible polymeric material. Todispense the composition, opposed wall portions of the vial are squeezedtogether by finger pressure to expel the composition through an outlet.The flexible wall portions are an advantage in that the user cancontrol, to some degree, the amount and flow rate of the compositionthat is dispensed. In addition, flexible wall portions are less likelyto break if the vial is unintentionally dropped or subjected to otherkinds of abuse in comparison to vials made of glass or other rigidmaterials.

Squeezable polymeric vials have been long used for various medical anddental preparations. Examples include vials for eye and ear medications,suntan and sun screen compositions, body lotions, cosmetics, topicalointments and insect repellents. Commercial and industrial applicationsinclude compositions for film developing and other photographicapplications, adhesives (such as cyanoacrylates), lubricants and thelike.

Many squeezable vials are made of polymeric material that issufficiently transparent or translucent so that the user may visuallyestimate the amount of a composition remaining in the vial. In someinstances, the transparent or translucent material helps the userascertain whether or not the composition has degraded. For example, theuser may be able to determine whether or not an adhesive has undulyhardened or thickened by shaking the vial and observing the fluidity ofthe contents through the polymeric wall portions.

Some compositions that are contained in squeezable vials are curableupon exposure to light having wavelengths in the visible spectrum.Examples of photocurable compositions include certain dental (includingorthodontic) adhesives and primers, dental luting cements and otherdental preparations such as sealants and crown build-up material. In thepast, vials containing such photocurable compositions have included asufficient amount of pigment, such as carbon black, that absorbs lightand blocks substantially all of the light from entering the chamber inthe vial that would otherwise unduly cure the contained composition.

Unfortunately, opaque squeezable containers are not entirelysatisfactory, since the user cannot visibly ascertain,the amount ofcomposition remaining in the vial or whether it has degraded. Somevials, and especially vials containing dental compositions, arerelatively small and contain only a small amount of photocurablecomposition. With such vials, it is difficult to determine the amount ofphotocurable composition remaining therein by lifting the vial andestimating its weight, since the ratio of the weight of the vial to theweight of the composition is relatively large.

SUMMURY OF THE INVENTION

The disadvantages noted above with respect to conventional squeezablevials have been overcome by the present invention. In one aspect, theinvention concerns a packaged composition that includes a vial formed bya bottom wall and an elastic side wall circumscribing the bottom wall todefine a chamber. The side wall has an upper section shaped to form anoutlet in open communication with the chamber. The bottom and side wallsare formed of a polymeric material having a colorant added thereto forsubstantially attenuating actinic radiation and at least upright portionof the side wall is capable of transmitting light having wavelengthsgreater than 500 nanometers substantially uniform wall thickness. Thepackaged composition further includes a photocurable material disposedin the chamber that is cured responsive to exposure of actinicradiation. The photocurable material is dispensed through the outletresponsive to portions of the side wall being displaced from an initialposition to a position closer together. The displaced portions of theside wall subsequently substantially return to the initial position.

Looking at the invention from another aspect, such concerns a packagedcomposition including a vial formed by a bottom wall and an elastic sidewall circumscribing the bottom wall to define a chamber. The side wallhas an upper section shaped to form an outlet in open communication withthe chamber. The bottom and side walls are formed of a polymericmaterial having a colorant added thereto for substantially attenuatingactinic radiation while minimally attenuating visible light having anapproximating spectral wavelength greater than 500 nanometers throughthe side wall. The colorant has a color in the orange portion of thevisible light spectrum. The side wall has a substantially uniform wallthickness. The packaged composition further includes a photocurablematerial disposed in the chamber and is cured responsive to exposure ofactinic radiation. The photocurable material is dispensed through theoutlet responsive to portions of the side wall being displaced from aninitial position to a position closer together. Subsequently, thedisplaced portion of the side walls substantially return to theirinitial position. The packaged composition also includes a label securedto an external surface of a first portion of the side wall and extendsfrom a position adjacent the bottom wall to a position adjacent theupper section thereof for enhancing visibility of a level of thephotocurable material through a second portion of the side wall.

From still another aspect, the present invention concerns a packagedcomposition that includes a vial formed by a bottom wall and an elasticside wall circumscribing the bottom wall to define a chamber. The sidewall has an upper portion shaped to form an outlet in open communicationwith the chamber. The bottom and side walls are formed of a polymericmaterial having a colorant added thereto for substantially attenuatingactinic radiation, while minimally attenuating visible light having anapproximating spectral wavelength greater than 500 nanometers throughthe side wall. The side wall has a substantially uniform wall thicknessin an approximating range of 0.015-0.025 inches. The packagedcomposition further includes a photocurable material disposed in thechamber and being cured responsive to exposure of actinic radiation. Thephotocurable material is dispensed through the outlet responsive toportions of the side wall being displaced from an initial. position to aposition closer together. Subsequently the displaced portions of theside wall substantially return to their initial position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of a packaged composition in accordancewith one embodiment of the invention, and wherein a vial is cut-away inpartial section in order to illustrate a quantity of the photocurablecomposition contained therein;

FIG. 1A is an enlarged sectional view of an upper portion of a vial sidewall of the present invention;

FIG. 2 is a side elevation view of a packaged composition according toanother embodiment of the invention;

FIG. 3 is a horizontal sectional view taken along line 3—3 of FIG. 2;

FIG. 4 is a side elevation view somewhat similar to FIG. 1 but inaccordance with yet another embodiment of the invention;

FIG. 5 is a horizontal sectional view taken along line 5—5 of FIG. 4;and,

FIG. 6 is a view somewhat similar to FIG. 5 except in accordance withstill another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A packaged photocurable composition according to one embodiment of theinvention is illustrated in FIG. 1 and is designated by the numeral 10.The packaged photocurable composition 10 broadly includes a vial 12 anda photocurable material 14 therein.

The vial 12 includes a bottom wall 20 from which extends an elastic sidewall 16 circumscribing the bottom wall to define a generally cylindricalinternal chamber 18 therein. The photocurable material 14 is receivedwithin the internal chamber 18.

The side wall 16 has an upper section 17 shaped to form a neck portion22 that terminates in an outlet 26. The neck portion 22 is provided witha threaded section 24 for coupling to a conventional threaded closurecap. The closure cap (not shown) has a dispensing opening and a closurefor selectively covering that opening. A similar closure cap isdescribed in U.S. Pat. No. 5,328,058, and such could be applied to thevial 12. Other types of dispensing outlets and closure caps may also beutilized.

The vial 12, including the elastic side wall 16 with its upper section17, and the bottom wall 20 are preferably integrally molded and made ofa polymeric material. The photocurable material 14 is dispensed from thevial 12 by displacing portions of the side wall 16 from an initialposition, such as where opposing sides of the vial are substantiallyparallel, to a position where the sides are displaced so as to be closertogether. The sides of the vial 12 are sufficiently elastic tosubstantially return to their initial position once the finger pressureof a user is released. Thus, in order for the vial 12 to be squeezable,the polymeric material from which it is formed should havp a flexuralmodulus that is preferably less than 200,000 kg/cm², and more preferablyless than approximately 20,000 kg/cm², and most preferably less than2,000 kg/cm². Referring additionally to FIG. 1A, the side wall 16 has athickness D that is preferably in the range of approximately 0.005-0.1inches (0.12-2.5 mm), and more preferably in the approximating range of0.01-0.06 inches (0.25-1.5 mm). Most preferably, side wall 16 shouldhave a thickness dimension D in the approximating. range of 0.010.03inches (0.25-0.75 mm).

As will be discussed in following paragraphs, it is important that thewall thickness be substantially uniform throughout the side wall 16.Therefore, as the side wall transitions to the upper section 17, boththe wall thickness C of the radiused portion 15 and the thickness B andA of the upper wall section 17 that transitions inwardly to form theoutlet 26 should all be substantially equal to the thickness D. Thus,for a vial having a nominal thickness of 0.020 inches for the dimensionD, the dimensions A, B and C should not vary more than ±0.005 inches inorder to maintain a proper level of electromagnetic radiation absorptionand transmissivity.

The flexural modulus and the thickness of the elastic side wall portions16 are selected to enable opposed sections of the wall portion 16 to bereadily squeezed together by finger pressure. As the opposed sectionsare squeezed together, free space in the chamber 18 is reduced and thephotocurable material 14 in the chamber 18 is expelled through theoutlet 26. The polymeric material from which the vial 12 is formed issufficiently elastic to enable the squeezed sections thereof to fullyself-recover from the deformed state to the original state of the vial,once the finger pressure is released, thereby re-assuming the normal,generally cylindrical configuration thereof.

As will be discussed in following paragraphs, another attribute of thepolymeric material utilized for vial 12 is its transmissivity of visiblelight, allowing a user to ascertain the level of the photocurablematerial 14 disposed in chamber 18. Suitable polymeric materials formaking the vial 12 include blow molded low density polyethylenes(“LDPE”) such as No. 5104 from CHEVRON, high density polyethylene(“HDPE”), polyvinyl chloride (“PVC”), poly(ethyleneglycol-co-cyclohexane-1,4-dimethanol terephthalate) (“PETG”), orpoly(ethylene terephthalate) (“PET”). The selected polymeric materialmust also be compatible with the photocurable material 14 and not undulydegrade over an extended period of time.

The photocurable material 14 is a liquid or semi-liquid material that iscurable upon exposure to selective actinic radiation, i.e., wavelengthsof light (electromagnetic radiation) that effects curing in thematerial. Examples of photocurable material include dental (includingorthodontic) adhesives and primers, luting cements, crown build-upmaterial and sealants. Such materials have a photoinitiator (such ascamphor quinone (“CPQ”) ) that initiates curing when exposed to actinicradiation, which may be a portion of the electromagnetic spectrum havinga wavelength less than 500 nm. The photocurable material 14 may also bea non-dental material such as a medical preparation or a compositionintended for household, commercial or industrial application. Theviscosity of the photocurable material must be within a range of valuesto be easily dispersed by squeezing portions of the side wall 16, andflow to the bottom of the chamber 18 without substantially coating theinternal surface of the side wall, and thereby inhibiting visualizationof the remaining portion of the photocurable material in the vial 12.Photocurable material 14 should have an absolute viscosity less than orequal to approximately 100 centipoise. With respect to kinematicviscosity, photocurable materials having viscosities within theapproximating range of 120-1200 centistokes have been successfullyutilized in the instant invention.

The vial 12 and in particular, the side wall 16 preferably transmitsless than approximately 1.0% of actinic radiation, and moreparticularly, transmits less than approximately 0.5% of actinicradiation. Most preferably, less than approximately 0.2% of actinicradiation is transmitted through the side wall 16. As a result, thephotocurable material 14 is able to remain in the chamber 18 for anextended period of time without unduly curing therein.

However, at least one upright portion of the side wall 16 must becapable of transmitting light having wavelengths greater than 500 nm, inorder to transmit sufficient light in the visible spectrum to allow auser to see the photocurable material 14 therethrough, whichphotocurable material may be a transparent liquid. In that way, thelevel of the material 14 in chamber 18 can be determined.

As an example, if the photocurable material 14 is a dental adhesive thatincludes the photoinitiator that comprises CPQ, the adhesive will beginto cure when exposed to light having wavelengths approximating 470 n.Preferably, the wall material of the vial containing the dental adhesiveblocks the passage of most of the light having such a wavelength, aswell as light having wavelengths relatively close thereto. In suchexample, the wall portions preferably transmit less than approximately1.0% of light having wavelengths in the range of 400 nm to about 500 nm.

In order to achieve the necessary wavelength sensitive transmittance,colorants such as pigments and/or dyes are useful for making thepolymeric material absorb selective wavelengths of impingingelectromagnetic radiation. The amount of colorant necessary per unit ofpolymeric material to provide the desired protection will vary dependingon a number of factors, such as the particular colorant selected, thethickness of the wall sections of the vial, the uniformity of the wallsections of the vial, the wavelength of light to be absorbed and thecapacity of the non-colorant treated polymeric material to absorb thelight in the wavelengths to be filtered.

A suitable colorant for the dental adhesive vial mentioned above is acolorant having a manufacturer's identification No. 70344 HCP fromTEKNOR COLOR COMPANY. The colorant is in the orange portion of thevisible light portion of the electromagnetic spectrum. While colorantsin the red portion of the spectrum have been found to suitably blockactinic radiation, such as wavelengths less than 500 nm, they do nottransmit sufficient visible light having wavelengths greater than 500 nmto allow a user to easily visualize the level of the photocurablematerial 14 within the vial 12. On the other hand, colorants within theyellow portion of the visible light spectrum transmit sufficient lighthaving wavelengths greater than 500 nm, but do not sufficientlyattenuate wavelengths less than 500 nm. It is a necessary requirement tosubstantially attenuate actinic radiation while minimally attenuatingvisible light having an approximating spectral wavelength greater than500 nm, and colorants in the orange wavelengths have been found to meetthat criteria.

The vial 12 may be made, for example, by mixing 6% by weight of thecolorant with 94% of the LDPE “carrier” resin. The resultant mixture isthen mixed with LDPE (such as No. 5104, from CHEVRON) at a “let-down”ratio of 5:1 (i.e., a ratio of five parts LDPE to one part carrier andcolorant mixture by volume). More accurately, the overall mixture ofcolorant and resin should have a colorant concentration of approximately1%. Preferably, the carrier resin has a slightly lower meltingtemperature than the melting temperature of the remaining quantity ofLDPE, to facilitate mixing. A suitable carrier resin is yukalon Lm-30from MITSUBISHI PETRO.

The amount of electromagnetic radiation attenuation is also dependentupon the thickness of the material through which the radiation passes.For vial 12, the side wall 16 has a thickness through which theelectromagnetic radiation passes. The thicker the side wall 16 is, thegreater the attenuation effect. However, as the vial 12 is intended tobe a “squeeze bottle” the wall thickness cannot be so thick as to impedethe displacement of opposing sides of the vial using only fingerpressure. Thus, once a vial polymeric material and thickness has beenselected, it then becomes critical that the wall thickness remainsubstantially uniform throughout the contours of the vial. As the uppersection 17 of the side wall 16 is contoured to form the neck 22 of thevial and terminate in the outlet 26, there are several radiused bends inthe cross-sectional contour of the vial. It is important that theseradiused regions have substantially the same thickness as the unradiusedportions thereof, in order not to attenuate less actinic radiationtherethrough, or attenuate too much light in the wavelengths greaterthan 500 nm. Thus, the thickness of the vial radiuses A and C should besubstantially equal to the wall thickness B and D. Similarly, thethickness of the side wall 16 where it interfaces with the bottom wall20 should have a thickness which is not less than the minimum end of theside wall thickness tolerance.

A packaged composition 10 a according to another embodiment of theinvention is illustrated in FIGS. 2 and 3. The packaged composition 10 aincludes a vial 12 a and a photocurable material 14 a therein.Preferably, the vial 12 a and the photocurable material 14 a are thesame or similar to the vial 12 and photocurable material 14 previouslydiscussed, except for the differences noted in the paragraphs thatfollow. As a consequence, a detailed description of such previouslydiscussed items will not be repeated.

As shown in FIGS. 2 and 3, the elastic side wall 16 a of the vial 12 aincludes a label 30 a that extends around the circumference of the vial12 a, and extends longitudinally along the length of the vial from aportion adjacent the bottom 20 a to a position substantially adjacentthe beginning of the upper section 17 a of side wall 16 a. The label 30a includes a first section 32 a that is opaque or substantially opaqueto the passage of light, especially light having wavelengths in thevisible spectrum. The label 30 a may also include a second section 34 athat is transparent or translucent to light having wavelengths in thevisible spectrum. Both of the sections 32 a and 34 a may be formulatedto block the passage of all or at least a substantial portion of actinicradiation.

The label 30 a may be made of any of a number of suitable materials,including polymeric film stock. Examples of suitable material includepolyethylene labels from FLEXCON COMPANY, INC. Optionally, the label 30a can be made of a co-extruded polyethylene film wherein the firstsection 32 a is made of an extruded mixture of polyethylene and black,white or other pigment, while the second section 34 a is simultaneouslyextruded from a stream of polyethylene without such pigment. As anotheralternative, the label 34 a may be made of transparent or translucentpolyethylene film and a quantity of ink applied to the first section 34a to render it opaque to the passage of light in the visible lightspectrum. As a further option, the second section 34 a is eliminated todefine a gap between opposing edges of the label 30 a, with thephotocurable material 14 a being viewed through the gap between opposingend portions of the label 30 a. The window created between the opposingedges of the label 30 a, or through the unpigmented section 34 a oflabel 30 a enhances the contrast between the photocurable material andthe air space above the photocurable material in the internal chamber18. As many of the photocurable materials which may be packaged in vial12 are substantially transparent, it is important that a contrastingbackground be created for viewing the height of the photocurablematerial within the vial 12. For vials 12 a of small size, it iscurrently not technically feasible to co-mold the vial itself with asingle portion thereof having a substantially transparent or translucentportion and a remaining portion being substantially opaque to visiblelight. Therefore, for such vials of small size, it is criticallyimportant that the label produce a substantially opaque section whichoccupies more than 50% of the circumference of the vial for providingcontrast to view the photocurable material through a remaining portionof the circumference of the vial, i.e. the portion 34 a.

Although not shown in the drawings, one side of the label 30 a is coatedwith a pressure-sensitive adhesive to firmly secure the label 30 a tothe upright side wall 16 a. An example of a suitable adhesive is a0.0008 inch (0.04 mm) thick layer of a permanent acrylic adhesive (No.V-157 from FLEXCON). Preferably, where the label 30 a includes atransparent portion 34 a, adjacent end sections of the label 30 aoverlap in order to reduce the likelihood of flagging and assure thatthe end portions of the label 30 a tightly adhere to the side wall 16 a.

As previously discussed, the label 30 a enhances the visibility of thelevel of the photocurable material 14 a in the vial 12 a when the useris viewing the photocurable material 14 a through the second portion 34a of label 30 a, or through the gap between end portions of the label 30a. Advantageously, since the first section 32 a also hinderstransmission of actinic radiation, there is less likelihood than anundue amount of actinic radiation will reach the photocurable material14 a.

Another embodiment of the invention is shown in FIGS. 4 and 5, wherein apackaged composition 10 b includes a vial 12 b and a photocurablematerial 14 b. Both the vial 12 b and the photocurable material 14 b arepreferably identical to the vial 12 and photocurable material 14previously described, except for the differences set out below.

The vial 12 b includes a float or element 40 b that is received in thechamber 18 b. The element 40 b has a density less than the density ofthe photocurable material 14 b, and as a result floats in thephotocurable material 14 b. The element 40 b is visible through the sidewall 16 b that transmits light in a portion of the visible lightspectrum, and thereby enhances the user's ability to determine the levelor amount of photocurable material 14 b in the chamber 18 b.

Prefqrably, the element 40 b has dimensions along two axes that aresmaller than the dimensions of the outlet 26 b so that the element 40 bcan be inserted into the chamber 18 b through the outlet 26 b after thevial 12 b is manufactured. As an example, if the chamber 18 b of thevial 12 b has an internal diameter of 0.64 inches (1.6 cm), the element40 b may have overall dimensions of 0.25×0.50 inches (6.4×13 mm) and athickness of 0.06 inches (1.5 mm). As illustrated in FIG. 5, the element40 b preferably has an overall generally oval-shaped configuration inplan view.

Preferably, the element 40 b has a thickness in the approximating rangeof 0.01-0.06 inches (0.25-1.5 mm). The flat shape and relatively smallthickness of the element 40 b helps the element return to a horizontalorientation after the vial 12 has been inverted and then returned to theupright vertical orientation as depicted in the Figures. Moreover, theflat shape of element 40 b tends to cast a more distinct shadow than afloat having, for example, a spherical shape, and as a result isrelatively easy to see through the side wall 16 b. Further, the element40 b may have a central hole 42 b. The hole 42 b improves fluid flow ofthe photocurable material 14 b to the outlet 26 b when the vial 12 b isinverted during a dispensing operation. The element 40 b is made of amaterial that is inert to the photocurable material 14 b. A suitablematerial for element 40 b that is inert to many photocurable materialsis polyethylene. The element 40 b could be a liquid, a semi-liquid (gelor paste) or a solid material that is either hollow or not hollow,including materials which are foamed.

Another embodiment of the invention is depicted in FIG. 6, wherein apackaged composition 10 c includes a vial 12 c and a photocurablematerial 14 c, the latter of which is identical to the photocurablematerial 14 described previously.

The vial 12 c has a generally oval-shaped overall configuration in planview. A threaded neck portion 22 c of the vial 12 c is identical to theneck portion 22, and may receive a cap of the type previously described.

The vial 12 c has an upright side wall 16 c which includes a firstsection 32 c that is preferably covered or at least substantiallycovered with a coating. Preferably, the coating is opaque or at leastsubstantially opaque to the passage of light in the visible spectrum aswell as in the actinic spectrum. An example of a suitable coating is anink that in applied by pad printing or screen printing technique andpreceded by a flame treatment to insure good adhesion of the ink to thevial 12 c.

The upright side wall 16 c includes a second portion 34 c which lacks orsubstantially lacks the coating that is applied to the first section 32c. As a consequence, the second section 36 c transmits more light in thevisible spectrum than the light transmitted to the first section 32 c,but still blocks actinic radiation by virtue of the colorant added tothe polymeric material of the vial.

Additionally, the vial 12 c includes a float or element 40 c that isreceived in the chamber. The element 40 c is somewhat similar to theelement 40 b, but is longer in length in order to better match the shapeof the chamber in plan view. The first section 32 c, the second section34 c and the element 40 help the user determine the level ofphotocurable material 14 c in the chamber.

Those skilled in the art may recognize that a variety of alternativesare possible to the presently preferred embodiments described in detailabove. For example, the shape of the vial may have anotherconfiguration, such as a configuration similar to squeezable tubes orsqueezable containers of other configurations, and could be made ofpolymeric materials and colorants different from those materials andcolorants previously set forth. Furthermore, the outlet could be open orcovered with a sponge, brush, swab or other type of applicator.Accordingly, the scope of the invention should not be deemed limited bythe specific descriptions mentioned above, but only by a fair reading ofthe claims that follow along with their equivalents.

What is claimed is:
 1. A packaged composition comprising: a vial formedby a bottom wall and an elastic side wall circumscribing said bottomwall to define a chamber, said side wall having an upper section shapedto form an outlet in open communication with said chamber, said bottomand side walls being formed of a polymeric material having a colorantadded thereto for substantially attenuating actinic radiation, said sidewall having at least one upright portion capable of transmitting lighthaving wavelengths greater than 500 nanometers, said side wall having asubstantially uniform wall thickness; and a photocurable materialdisposed in said chamber and being cured responsive to exposure ofactinic radiation, said photocurable material being dispensed throughsaid outlet responsive to portions of said side wall being displacedfrom an initial position to a position closer together, subsequentlysaid displaced portions of said side wall substantially returning tosaid initial position.
 2. The packaged composition as recited in claim 1where said substantially uniform wall thickness is within anapproximating range of 0.015-0.025 inches.
 3. The packaged compositionas recited in claim 1 where said polymeric material has a flexuralmodulus less than approximately 200,000 kg/cm².
 4. The packagedcomposition as recited in claim 1 where said polymeric material has aflexural modulus less than approximately 20,000 kg/cm².
 5. The packagedcomposition as recited in claim 1 where said photocurable material haseither an absolute viscosity less than 100 centipoise or a kinematicviscosity less than 1200 centistokes.
 6. The packaged composition asrecited in claim 1 where said side wall transmits less than 1.0% actinicradiation.
 7. The packaged composition as recited in claim 1 where saidside wall transmits less than 0.5% actinic radiation.
 8. The packagedcomposition as recited in claim 1 further comprising a label secured toan external surface of a first portion of said side wall and extendingfrom a position adjacent said bottom wall to a position adjacent saidupper section thereof for enhancing visibility of a level of saidphotocurable material through a second portion of said side wall.
 9. Thepackaged composition as recited in claim 1 where said colorant has acolor in the orange portion of the visible light spectrum.
 10. Thepackaged composition as recited in claim 9 where said colorant is addedto said polymeric material to provide a colorant concentration ofapproximately 1%.